Opinion on helicoils

[thibs101]

Hey there im new to this site and this will be my first post. I just bought my first bike a 300ex cheap! and yess it was to good to be true sadly...... When i got it the rear hubs we grinded and every thing on the bike was Fkd. so i took a look at the engine and there was 7 bolts on the valve cover that were striped and filed with JB weld. ive been riding it like that for a while now but im geting sick and tired of having oil all over my pants and bike. i wass looking to helicoil the holes to the original size of a M6x 1.0 but the helicoil tap drill size is a 1\4 inch and the holes are already over that. soo im thinking of using 1\4 20 helicoils instead the tap drill size seams to be closer to the over sized hole but im not shure if the helicoils in aluminum will be strong enough to hold the valve cover. anny in put on this be 4 i trie it?

Thanks
Marc T

[HondaPohl]

Helicoils should be your last option imo but its better to try before you buy a new cylinder. They will hold your valve cover down with no problem. I no the feeling of taking peoples abortions and trying to fix them. Some people shouldnt be allowed to use tools or own something nice.

[CJM]

I would much prefer to get 7mm or 1/4 bolts and drill and tap it properly if possible. Helicoils are nice, but once they are in the hole is to large to work with should something happen and you can use a helicoil any longer.

[beyer05]

Heli-coils should work fine.

[Thumpin440ex]

Heli's work fine, esp for a valve cover situation.. Unless you have time, want to go through the process of drilling and tapping fresh holes..


John

[wilkin250r]

What are the torque specs?

I would say that helicoil repair is probably just as strong as original threads in aluminum. Aluminum isn't super strong anyways, and think about the forces acting on a thread as they strip out. You have the pulling force, but you also have grinding abrasion force acting on the threads as they turn.

The helicoil insert is steel, so it will handle the abrasion force much better, leaving only the pulling force against the aluminum. If the original threads could handle both forces, I would imagine the re-cut threads could handle the pulling force alone.

If you're still worried about strength, get a solid insert like timeserts or similar. They handle the abrasion force, and since they are solid, any pulling force will be spread across all the threads instead of just a few.

[thibs101]

thanks for the input i got it done and it works great!!!! but then i riped my sproket off the shaft and busted my casse...... so much for a cheap bike eih?